This invention relates to aromatic compounds and more particularly to aromatic compounds containing nitro groups.
HNS-I is used in explosive actuating devices, detonating cords, flexible shape charges, etc. The HNS-I which is produce by conventional processes is crude and therefore has a low thermal stability. Washing the crude product with solvents only removes the surface contaminants; impurities which have cocrystallized or occluded with the product HNS-I are not removed. Another method of purification is to dissolve the crude HNS-I in hot fuming nitric acid and then allow the solution to slowly cool to room temperature. This method produces pure HNS-II. (HNS-II differs from HNS-I primary in that HNS-II has a significantly larger particle size.) Because of its larger particle size, HNS-II is less suitable for use in applications such as detonation cords or flexible shape charges. In devices such as these, particle size is so important that impure HNS-I is frequently used instead of pure HNS-II. Yet another approach is to digest the crude HNS-I by heating it in organic solvents; however, crystal growth occurs during this procedure and a wide particle size distribution results. There have been a variety of situations where pyrotechnic devices loaded with this treated HNS-I have failed because of faulty loading caused by the unusually wide particle size distribution.